Question: $\overline{AC}$ is $6$ units long $\overline{BC}$ is $9$ units long $\overline{AB}$ is $3\sqrt{13}$ units long What is $\cos(\angle BAC)$ ? $A$ $C$ $B$ $6$ $9$ $3\sqrt{13}$
SOH CAH TOA os = djacent over ypotenuse adjacent $= \overline{AC} = 6$ hypotenuse $= \overline{AB} = 3\sqrt{13}$ $\cos(\angle BAC )=\frac{6}{3\sqrt{13}}$ $=\dfrac{2\sqrt{13} }{13}$